!?, 1boy, 1girl, a tea, ahoge, arknights, arms behind back, bikini, bound, bound arms, chinese text, doctor (arknights), goggles, goggles around neck, greyscale, la pluma (arknights), la pluma (summer flowers) (arknights), looking at another, monochrome, navel, official alternate costume, rope, shibari, short hair, surprised, swimsuit, thigh strap, tying